Hello dear, yes it is more than sufficient if you just ask for GRE exam but getting admission in best colleges demands many more things except your GRE score, such as  a very good academics performance in your college, very strong recommendation letter and if you want scholarships and all then you will be needing a good research experience and some published papers too.

I know all this sound very complicated but if your are dedicated and ready to work hard , it not the big deal.

So in your 1st year enjoy your new life but don't ignore your academics and start working on your english.

Next in 2nd year take projects under your college profs and in summers go for research internships.

In 3rd year work on your project and your goal must be to publish a paper or 2.

And after doing all these , I think you will br able to decide what you have to do in your 4th year.

ALL THE BEST!!!

Atleast 6 month before your GRE Exam you should start your preparation ..

Basic Tips to Prepare for GRE and Test Papers:

Make a strategy and follow it  religiously to study regularly for each section. Every section of GRE is  unique, thus require diverse preparation.

Be thorough with analytical writing.  This section measures candidates’ focus, intelligence for discussion and  their ability to put forth complex ideas with suitable examples. To  gain mastery over analytical skills, read a lot especially articles on  diverse topics and try to analyze them with varied perspectives.

Keep your knowledge bank updated. Be  aware of national and international important happenings and events.  Read regular national dailies and magazines that contain information of  latest occurrences of the world. Follow televisions and internet for the  same.

Practice for quantitative reasoning.  This section evaluates candidates’ skills to study and interpret the  quantitative issues and how they can use their mathematical skills to  solve them. Subjects like geometry, algebra, arithmetic, probability and  statistics are included. Practice and clarity of concepts can make you  score higher.

Get complete hold of verbal reasoning  section by prior practice. This section examines the ability of the  aspirants to comprehend what they have read and how they draw and  investigate conclusions out of it. Read as much as you can English  language materials. Also analyze and write as much as you can.

To prepare for GRE select the  preparation books with care. The books should cover all relevant topics  of each and every section of the exam. You can also download study  material from government’s GRE website. Downloading software like  POWERPREP II would be of great help to get acquainted with the tests in  terms of time, questions test design, on-screen calculator and testing  software.

Before starting the exam read the questions carefully, understand what answer is required and then start answering.